After upgrading to Kubuntu 9.04 and KDE 4.3, Quanta Plus was removed due to file dependencies not being met. To resolve the issue, perform the following steps (any 32 bit versions will need to find these packages built for 32 bit systems).
wget http://launchpadlibrarian.net/17069296/kxsldbg_3.5.10-0ubuntu1_amd64.deb
wget http://launchpadlibrarian.net/17069294/kommander_3.5.10-0ubuntu1_amd64.deb
wget http://launchpadlibrarian.net/17069293/klinkstatus_3.5.10-0ubuntu1_amd64.deb
wget http://launchpadlibrarian.net/17069291/kfilereplace_3.5.10-0ubuntu1_amd64.deb
sudo dpkg -i k*.deb
sudo apt-get install quanta